Posted: 10/01/2016 at 19:36
the variety Susan is the most reliable magnolia. nice and compact. Wont exceed your height limit
magnolias dont like being pruned too much or moved so a large container would be a solution. Shelter from cold winds and an acid soil (not essential but preferable). Use ericacious john innes compost.
In my experience magnolias can be temperamental though.
enjoy your magnolia